The god of doom and judgement and the keeper of the House of Spirits in Tolkien's epic novel The Silmarillion. Námo alone of the Valar knows all that shall come to pass, save that which lies still in the freedom of Ilúvatar.

"Námo Mandos is the Doomsman of the Valar; but he pronounces his dooms and his Judgements only at the bidding of Manwë."